Tomorrow is Easter, and today tons of kids are going to their local parks for Easter Egg hunts.
Did you know that all over the world, everyday, people go on Easter Egg Hunts? Not searching for the pastel boiled eggs that stink if you happen to forget where you hid them. Instead, they are looking for little things hidden by directors, gamemakers, and yes- authors, in their favorite media. An Easter Egg in this sense could be defined as a little goodie placed in books, games or film that don't add to the plot, but add humor or an extra dimension to the story. They are usually not obvious and only a reader who is paying attention will find them. Think those golden eggs in Angry Birds. Disney is famous for their "Hidden Mickeys" in all their films, and even in their themeparks. They also have a habit of making jokes or references to favorite stories or characters from other books.
A good writer will do this too. A book can be enjoyable as a surface read, but it's really fun to add things - like little treats or even signposts- that you might only catch after reading once. It can be like a really subtle foreshadow. If your story is one of betrayal, then in one scene your MC might have a famous book on the nightstand that has a similar theme.
If you are doing a retelling, Easter Eggs are a great way to pay homage to the original work. I did this a lot in my book, House of Emerald. It's a twist on Oz. The story stands on it's own, but for any fan of Baum's original work, their are lots of fun little twists and references to his odd world. Talking dinnerware, hammerheads, and other fantastical things. On one level for the average reader, it aids me in world building a fantastical place. For a lover of fairytales and Oz, it keeps the reader on their toes looking for more things they recognize. In fact, aside from my narrative voice, the use of Easter Eggs with humor is one of the main reason my agent picked me up.
So get yourself noticed and start playing the Easter Bunny in your own writing.